Process of manufacturing artificial silk and other products from nitrocellulose



lt eitentetl c.len 5 9, i923 DSCHEDLER, OF PHILADELPHIA, PENNSYLVANIA, AND GEORGE JUER, OE QIPEWnJLL, VIRGINIA, ASSIGNORS TO TUBIZE ARTIFICIAL SILK COMPANY OF AMERICA, WILMINGTON, DELAWARE, A CORPORATION OF DELAWARE.

ZEROCESS 0F IVZANUFACTURING ARTIFICIAL SILK AND OTHER PRODUCTS FROM NITROCELLULOSE.

No Brewing.

To all 7.01 101% it may 6.041067%:

Be it known that we, EMILE Bmnsonnn- LER, citizen of the Republic of Switzer-= land, and resident of Philadelphia, in the 5 county of Philadelphia, in the State of Pennsylvan a, and (lsonon Jenn, recently a subject of the former Austro-Hungarian Empire, and now a resident of Hopewell, in-

of articles t' rom nitrocellulose and particusrly to the production of artificial silk. Heretofore it has been known that acetone and its homologues are solvents of nitrocellulose and that its or their use as such would be aovanta 'eous from the point of view of the compr tively easy and percentage ofthei' ecove y "from admixture with air, com, o w oh other solvents, the large losses of w rich more than offset their relative cheapnesst lt has been found, however, that acetone as heretofore attempted to be used, results in a cloudiness or opacity in the finished product made from the ace- 30- tone collodion and, particularly it is found that artiticir silk so made triahlc and without his vention to provide a i Wi g" acetone as a solvent for nil for recovering the nitroce'h lulose iroin solution after manufacture which will noduce a lustrous and strong filament or other product, and we accomplish thisiirst, by i'lehyllratingg nitrocellulose hydra-re, preterahly by treating it with ethyl alcohol hich substance need not be climinatcd e treated nitrocellulose before it hrotght into solution; second, we treat dehyr ted i'll'tlOCfifllHlOSO with dry acetone or it homologues to form an acetone collodion; .iird, we the acetone rollodion the desired harm of the finished product by well known processes; in the manufac- Application filed November 19, 1920.

Serial No. 425,048.

ture of artificial silk, by forcing it through spinnerets, lastly,we extract the acetone 50 solvent from the product by evaporation in warm dry air containing 50% or less moisture and heated to from to C. The acetone can afterwards he denitrated, if desired, by well known methods. The use of the dry or dehydrated nitrocellulose and of the dry acetone avoids, we have found, the detrimental effect of acetone on nitrocellulose observable in the metllods of use heretofore tried, and while an improved product will beobtained with almost any process for removing the solvent, 1k is best that it should he removed under conditions which will avoid the hydration of the nitrocellulose or acetone during the extraction of the solvent. 'rlherefore we extract the solvent in the manufacture of artificial silk by passing the filament as formed through a current of warm dry air which will carry off the solvent without hydration and from which a very full recovery of acetone can be made by well known methods; for instance, by passing the solvents in admixture with air through a series of towers into which water is sprayed in the familiar counter current method.

Instead of using acetone its well known houiologucs can be used, such for instance, as acetone oils, methyl acetone, etc. and the solvent can be made up of mixtures of these or of mixtures of acetone or its homologu'es with other solvents of nitrocellulose,such as ethyl alcohol. w

Hai in g' now described our invention, what we claim new and desire to secure 5 by Letters Patent, is:

1. The method of manufacturing clear, unclouded products from nitrocellulose which consists in dehydrating nitrocellulose hydrate by treating it with ethyl alcohol, dissolving: it, while still containing adhering ethyl alcohol, in a solvent made up in Whole or in part ot dry acetone or its homologues, gi sing to the rollodion thus obtained the desired 'form and finally extracting the solrent by evaporation in warm dry air con- 1 cial silk filaments from nitrocellulose which consists in dehydrating nitrocellulose hy- 6 drate by treating it with ethyl alcohol, dissolving it, while still containing adhering ethyl alcohol, in a solvent made up in whole or in part of dry acetone oreits homologueig giving to the collodion thus obtained; the ilesired form and finally exeracting the solvent 1e by evaporation in Warm dry air oonmining not to exceed fifty per cent moisture.

EMILE BINDSGHEDLER. GEORGE JUER. 

